The invention relates to a programmable control for a switching chronometer or timer comprising a magnetic field sensor, and in particular a sensor having a ferromagnetically alloyed wire that is disposed on a program carrier. A coil is brought into the proximity of the wire. A permanent magnet adjacent thereto has a magnetic field which influences the core polarity of the wire such that the coil emits voltage pulses given polarity changes for the control of an electric or of an electronic switch means.
It is necessary given such chronometers or timers, particularly given switch clocks, cycle control timers or time lag relays to cite only a few applications for such devices, that one or more switching times can be simply and surveyably programmed with adequately fine graduations both for the desired cut-in time as well as for the desired cut-out time. It should thus be assured that a programmable control means which can not only be economically manufactured in terms of production engineering but which can also be universally and handily employed in such devices can be obtained upon employment of a magnetic field sensor whose manner of functioning is based on the known, so-called Wiegand effect.
It is known to employ such magnetic field sensors for reading programmable data storages wherein, for example given an identity card, the wires are embedded in plastic such that the wires having a specific length of approximately 15 mm are disposed axially displaced relative to one another according to a specific program pattern wherein the wires are aligned axially parallel to one another. This non-variable program pattern on such a program carrier is read by a read head which is essentially equipped with a coil and with a permanent magnet adjacent thereto. The read head or the program carrier can be linearly or rotationally moved for the purpose of reading (reprint from Elektronik, No. 7/80, incorporated herein by reference).
This known apparatus is handicapped by the disadvantage that the ferromagnetic wires impressed, injected, or bonded in the program carrier are non-releasably disposed and are thus not arbitrarily reprogrammable, particularly for the non-technician.